Naphthalimide appended isoquinoline fluorescent probe for specific detection of Al3+ ions and its application in living cell imaging

Herein, a novel Schiff base fluorescent probe NIQ based on naphthalimide and iso-quinoline units has been readily prepared for the selective detection of Al³⁺ ions. The obviously visible color changes and prominent fluorescence enhancement were observed upon the addition of Al³⁺ to NIQ, which could be attributed to the complexation of NIQ with Al³⁺ and thus leading to the inhibition of photo-induced electron transfer (PET) and the chelation-enhanced fluorescence (CHEF) progress. The limit of detection (LOD) was 52 nM that was far below the standard recommended by the WHO. Binding ratio (1:1) of NIQ with Al³⁺ ions was supported by Job's plot. The binding constant of NIQ for Al³⁺ were calculated to be 3.27 × 10⁵ M^-1 on the basis of benesi-Hildebrand plot. The plausible binding mechanism for NIQ towards Al³⁺ ions was evidenced by the density functional theory (DFT) and ¹H NMR titration experiment. Furthermore, this "turn-on" probe NIQ has been successfully applied as a biomarker for imaging the Al³⁺ ions in living cells.

Synthesis and crystal structures of two tri- and tetra-heterometallic Ni(ii)–Mn(ii)/Ni(ii)–Co(iii) complexes from two different Ni(ii)-containing metalloligands: effective catalytic oxidase activity and Schottky device approach

The development of tri- and tetra-nuclear heterometallic Ni(ii)–Mn(ii)/Ni(ii)–Co(iii) complexes with effective catalytic oxidase activity and the Schottky device approach.

Idiosyncratic recognition of Zn2+ and CN- using Pyrazolyl-Hydroxy-Coumarin scaffold and live cell imaging: Depiction of Luminescent Zn(II)-Metallocryptand

Multi-responsive sensitive and selective sensor design is one of the stimulating researches in sensor field. We have designed a pyrazolyl-hydroxy-coumarin scaffold, 7-hydroxy-4-methyl-8-(((5-phenyl-1H-pyrazol-3-yl)imino)methyl)-2H-chromen-2-one (H2L) and characterized by spectroscopic data (1H-NMR,13C-NMR, ESI-MS,...

A novel reversible fluorescent probe based on naphthalimide for sequential detection of aluminum (Al3+) and fluoride (F-) ions and its applications

A new Schiff base fluorescent probe NBP derived from the one-step condensation strategy of 2-butyl-6-hydroxy-1,3-dioxo-2,3-dihydro-1H-benzo[de]isoquinoline-5-carbaldehyde and N-(2-(hydrazinecarbonyl)phenyl)benzamide was synthesized and characterized. NBP exhibited high selectivity toward Al³⁺ along with naked-eye color changes and prominent fluorescence enhancement. The limit of detection (LOD) of NBP toward Al³⁺ was detected to be 80 nM. The binding ratio of NBP with Al³⁺ ions was obtained as 1 : 2 on the basis of Job's plot with the association constant K_a value of 4.22 × 10¹⁰ M^-1/2. The plausible complexation mechanism of NBP toward Al³⁺ ions was validated by the density functional theory (DFT) and IR spectrum. In addition, in situ formed "NBP + Al³⁺" could be utilized as the second sensor for selective recognition of F^-via fluorescence quenching with a low detection limit (44 nM). Furthermore, the cell imaging experiments of probe NBP in HeLa cells have successfully demonstrated that NBP could serve as an indicator for monitoring Al³⁺ ions in living cells. On top of that, NBP could be used to prepare simple test paper strips for quickly and qualitatively detecting a trace amount of Al³⁺ ions in a visible manner.

Recent advances in the development of fluorescent chemosensors for Al3

Detection of Al3+ has become important as it is related to several health issues and other problems. Different fluorophoric platforms, such as naphthalene, benzene, rhodamine, etc., have been explored to sense Al3+ and a good number of research articles are being published. This article focuses on the synthesis of recently reported aluminum sensors constructed from 2-hydroxy-1-naphthaldehyde, salicylaldehyde, rhodamine, coumarin and different metal based-MOFs.

A purine based fluorescent chemosensor for the selective and sole detection of Al3+ and its practical applications in test strips and bio-imaging

A novel purine Schiff base fluorescent probe (WYW), (E)-4-methyl-2-((2-(9-(naphthalen-1-yl)-8-(thiophen-2-yl)-9H-purin-6-yl)hydrazono)methyl)phenol, was designed and prepared as an excellent reversible fluorescent chemosensor for monitoring Al³⁺. The fluorogenic "turn-on" sensor WYW exhibited high selectivity towards Al³⁺ over other coexistent metal ions, accompanying with an obvious visual color change in DMSO/H₂O (9/1, v/v, pH = 7.4) media. The enhancement fluorescence of WYW could be attributed to the inhibition of PET and ESIPT process induced by Al³⁺. Notably, the WYW-Al³⁺ complex exhibited a fluorescence "turn-off" response towards F^- with exceptional selectivity via the displacement approach. The detection limit of WYW for Al³⁺ was calculated to be as low as 82 nM. The formation of complex WYW-Al³⁺ (1:1 stoichiometry) was confirmed by Job's methods and further verified by density functional theory (DFT) calculations. Furthermore, the probe WYW with low cytotoxicity and excellent membrane-permeable property has also been successfully applied for detecting low concertation Al³⁺ in living HeLa cells.

A novel phenolphthalein-based fluorescent sensor for Al3+ sensing in drinking water and herbal tea samples

In this study, 3,3-bis(4-hydroxy-3-((E)-((4-hydroxyphenyl)imino)methyl) phenyl)isobenzofuran-1(3H)-one (HMBP) was designed as a ''turn-on″ fluorogenic chemosensor to detect Al³⁺. Studies were performed in C₂H₅OH-HEPES (v/v, 9/1, pH 7.0) media at λ_em = 475 nm. The LOD value was found to be 0.113 µM. The stoichiometric ratio of HMBP-Al³⁺ was determined as 1:2 by Job's plot and ESI-MS as well as ¹H NMR titration. The binding constant of chemosensor HMBP with Al³⁺ from the Benesi-Hildebrand equation was determined to be 1.21 × 10⁸ M^-1. The quantum (Φ) yields were obtained as 0.040 and 0.775 for the chemosensor HMBP and HMBP-Al³⁺, respectively. The response of the chemosensor HMBP towards Al³⁺ was attributed to the strategies of blocking the photo-induced electron transfer (PET) and CN isomerisation mechanisms. Finally, the sensing of the chemosensor HMBP for the determination of Al³⁺ in real food samples, drinking waters and herbal teas, were employed.

Chromogenic and fluorogenic “off–on–off” chemosensor for selective and sensitive detection of aluminum (Al3+) and bifluoride (HF2−) ions in solution and in living Hep G2 cells: synthesis, experimental and theoretical studies

A simple pyridine-dicarbohydrazide based colorimetric and fluorometric chemosensor L was designed and synthesized for Al³⁺ ion sensing in organo aqueous solution.

Designing of Pb(II)-Based Novel Coordination Polymers (CPs): Structural Elucidation and Optoelectronic Application

[Pb₂(bdc)_1.5(aiz)] _n (1) and [Pb₂(bdc)_1.5(aiz)(MeOH)₂] _n (2) (H₂bdc = 1,4-benzene dicarboxylic acid, aiz = (E)-N'-(thiophen-2-ylmethylene)isonicotinohydrazide) have been synthesized, and structural characterization has been established by X-ray analysis and thermogravimetric analysis (TGA). Here, bdc^2- links two Pb(II) centers and the aiz ligand binds the metal centers in two different manners: chelating and monodonating. Thus, polymerizations have taken place from the combination of mixed ligand system. Optical band gaps have been studied via UV measurements. Again, the experimental and calculated (from density functional theory (DFT)) band gaps agree well and the semiconducting properties of synthesized polymeric materials have been approved. Thus, optoelectronic and photonic devices can be made by this type of coordination polymers (CPs). The I-V representative curves of 1 (device-A) and 2 (device-B) in both dark and illuminated conditions show that device-A has a higher magnitude of current than device-B. Dark- and photo-conductivity values of device-A are calculated as 2.94 × 10^-6 and 6.12 × 10^-6 S m^-1, respectively, whereas for device-B, the values of dark- and photo-conductivity are 2.92 × 10^-7 and 3.66 × 10^-7 S m^-1, respectively, at room temperature.